Enzymes have been used for a long time for a variety of different industrial applications. Examples are known in the baking industry, in the wine and fruit juices industry (where enzymes are used to break down pectins and β-glucans), in the textile industry (where cellulases are used to obtain soft and smooth cellulosic fabrics) and also, which is not the least application, for animal feed. In this case the enzymes improve the digestibility of vegetable sources.
This last use enables the livestock to digest feed more efficiently. The value of a feed can be measured by the FCR (Feed Conversion Ratio), a nutritive ratio of the amount of feed consumed relative to the weight gain of the animal. A decrease in FCR, for a feed. indicates the animal gains proportionately more weight for a given quantity of feed; i.e. the animal is able to utilize the feed more efficiently.
Poor digestibility of the feed components (starch, fat, protein/amino acids) is a noted feature of cereal-based feeds and, for example, particularly those containing a high barley or wheat content. In these cases it may be necessary to formulate the teed to contain higher levels of energy from other sources and other supplements such as amino acids. These enzymes increase the Apparent Metabolizable Energy value of the cereals incorporated into the feed.
Another approach to resolve this problem has been to add enzyme supplements, cellulases, endo-1,3(4)-β-glucanases (β-glucanases), endo-1,4-β-xylanases (xylanases) etc., or mixtures of enzyme activities, to these cereal-based feeds. Enzyme supplements may have a specific use to hydrolyze the B-glucans, or to hydrolyze the arabinoxylans, found in the cereals (typically barley and wheat). The addition of enzymes has different goals. One advantage which clearly proves the efficacy of feed enzyme supplements is the reduction in viscosity of materials in the gut of the animals which receive cereal-based feed containing the appropriate enzyme supplement. The higher viscosity is due, in part, to β-glucans and arabinoxylans found in barley and wheat. The lower viscosity, resulting from enzyme action, permits an easier absorption of nutritional components in the animal's gut. The other advantage is the release of nutrients entrapped by the cell walls of the cereals decreasing the requirement for other costly feed supplements. Overall the result is a significant reduction in the cost of the feed with a similar or beneficial effect as measured by the FCR.
Enzymes preparations originating from a range of different micro-organisms have been described to improve feed digestibility.
If we consider prior art related to the use of enzymes in the animal feed we can mention the European Patent No 0.699.762 which describes use of a phytase issued from Schwanniomyces occidentalis. This phytase is a phytase obtained from genetically modified organism obtained by including cloned gene that we would like to avoid in the present invention.
It we consider the WO 95/26398 patent application, again a modified cellulase is obtained by inclusion of foreign DNA sequence in an host cell which modifies the nature of the original strain which is chosen in the following list of micro-organisms : Bacillus, Streptomyces, Saccharomyces, Schizosaccharomyces, Aspergillus. In the present invention our main aim was to avoid foreign gene inclusion in the micro-organism which is the producer of the enzyme.
In the WO 96/05739 patent application, a mixture of enzymes (xylanase, protease and, optionally, β-glucanase) is obtained from different micro-organisms. The authors give example (page 5) of enzymes mixture with a ratio of xylanase activity to β-glucanase activity of the order of 1:5. It has been found that when a xylanase is included in a cereal-based diet at or around its optimum dosage level, the co-presence of enzymes possessing β-glucanase activity increases the FCR of the feed which is of course disadvantageous. Consequently the authors advise against the presence of β-glucanase, they recommend a maximum ratio of xylanase activity to β-glucanase activity of 1:0-0.25.
In some cases, in order to ensure all the enzyme activities relevant to the feed application are present, preparations are made up from preparations from more than one micro-organism. In a number of cases the enzyme preparations have been obtained from microorganisms subjected to genetic modification using recombinant DNA techniques.
We have discovered and developed a new micro-organism belonging to the class of Penicillium funiculosum, that contains new enzymes and a mixture of enzyme activities which can be used successfully to increase mainly the digestibility of cereal-based animal feeds.